HIV-1 drug resistance mutations are present in six percent of persons initiating antiretroviral therapy in Lusaka, Zambia

High prevalence of HIV-1 transmitted drug resistance and factors associated with time to virological failure and viral suppression in Taiwan

BACKGROUND

Integrase strand transfer inhibitor (InSTI)-based regimens have become the major first-line treatment for HIV-1-infected patients in Taiwan. Transmitted drug resistance (TDR) and several clinical characteristics are associated with time to virological failure or viral suppression; however, these have not been investigated in Taiwan.

OBJECTIVES

To determine the impact of several factors on treatment outcomes in HIV-1-infected patients in Taiwan.

METHODS

The cohort included 164 HIV-1 treatment-naive patients in Taiwan from 2018 to 2020. Blood specimens were collected to determine the genotypic drug resistance using the Stanford University HIV drug resistance database. Cox proportional hazards models were used to identify factors associated with time to virological failure or viral suppression.

RESULTS

The prevalence of TDR in Taiwan was 27.4% and an increasing trend was seen from 2018 to 2020. TDR mutations related to NNRTIs were the most prevalent (21%) while TDR to InSTIs remained at a relatively low level (1.3%). A baseline HIV-1 viral load of ≥100 000 copies/mL was associated with a shorter time to virological failure [multivariate hazard ratio (mHR) 7.84; P = 0.018] and longer time to viral suppression (mHR 0.46; P < 0.001). Time to viral suppression was shorter in patients receiving InSTI-based regimens (mHR 2.18; P = 0.006). Different InSTI-based regimens as initial treatment did not affect the treatment outcomes.

CONCLUSIONS

This study found an increasing trend of HIV-1 TDR prevalence from 2018 to 2020 in Taiwan. Baseline HIV-1 viral load and receiving InSTI-based regimens are important factors associated with time to virological failure or viral suppression.

Pretreatment HIV Drug Resistance Among Adults Initiating or Re-Initiating First-Line Antiretroviral Therapy in Zimbabwe: Fast-Tracking the Transition to Dolutegravir-Based First-Line Regimens?

Pretreatment drug resistance (PDR) can compromise antiretroviral therapy (ART) efficacy and undermine the WHO targets to end the AIDS epidemic as a public health threat by 2030. Thus, we examined the level of PDR in Harare, Zimbabwe. Eligible study participants were adults who were ART naive or individuals with previous ART exposure reinitiating treatment, recruited between October 2018 and February 2020 in a HIV ART treatment clinic, in Harare. HIV drug resistance tests were performed for all specimens with viral load ≥400 copies/mL and interpreted using the Stanford HIVDB Algorithm. Chi-square test or Fisher's exact test was used for comparison of proportions of PDR across ART-naive or prior ART-exposed participants. All statistical analyses were performed using Stata version 14. Overall, 120 samples were genotyped of whom 104 were ART naive and 16 reported previous ART exposure. The overall PDR frequency among all participants was 31% [95% confidence interval (CI): 22.5-39.6]. PDR to any non-nucleotide reverse transcriptase inhibitor (NNRTI) was reported in 29% (95% CI: 21.0-37.9). PDR to nucleotide reverse transcriptase inhibitors (NRTIs) and protease inhibitors were low, found in 3% (95% CI: 0.9-8.2) and 1% (95% CI: 0.02-4.52), respectively. PDR to NNRTIs [efavirenz/nevirapine (EFV/NVP)] was found in 17% (95% CI: 10.5-24.6) and was more than six times higher among people with previous ART exposure than ART-naive people: 63% versus 10%, p < .001. Our study shows that PDR to NNRTIs in Zimbabwe has remarkably increased from the 10.9% prevalence reported in the 2016 WHO survey. Addressing PDR at a national level is a critical need and will be facilitated by fast-tracking the transition to dolutegravir in first-line ART regimens.

Evaluating the impact of antiretroviral and antiseizure medication interactions on treatment effectiveness among outpatient clinic attendees with HIV in Zambia

OBJECTIVE

Interactions between enzyme-inducing anti-seizure medications (EI-ASMs) and antiretroviral drugs (ARVs) can lead to decreased ARV levels and may increase the likelihood of viral resistance. We conducted a study to determine if co-usage of ARVs and EI-ASMs is associated with ARV-resistant human immunodeficiency virus (HIV) among people living with HIV in Zambia.

METHODS

Eligible participants were ≥18 years of age and concurrently taking ASMs and ARVs for at least 1 month of the prior 6-month period. Data were obtained regarding medication and HIV history. CD4 counts, plasma viral loads (pVLs), and HIV genotype and resistance profile in participants with a pVL >1000 copies/mL were obtained. Pearson's test of independence was used to determine whether treatment with EI-ASM was associated with pVL >1000/mL copies.

RESULTS

Of 50 participants, 41 (82%) were taking carbamazepine (37 on monotherapy), and all had stable regimens in the prior 6 months. Among the 13 ARV regimens used, 68% had a tenofovir/lamivudine backbone. The majority (94%) were on a stable ARV regimen for >6 months. Median CD4 nadir was 205 cells/mm³ (interquartile range [IQR] 88-389), and 60% of participants had commenced ARV treatment before advanced disease occurred. Mean CD4 count at enrollment was 464 cells/mm³ (SD 226.3). Seven participants (14%) had a CD4 count <200 cells/mm³ . Four (8%) had a pVL >1000 copies/mL; all were on carbamazepine. Three participants with elevated pVL had a CD4 count <200 cells/mm³ . None had documented adherence concerns by providers; however, two had events concerning for clinical failure. HIV genotype testing showed mutations in three participants. Carbamazepine was not found to correlate with elevated pVL (P = .58).

SIGNIFICANCE

EI-ASMs are commonly used in sub-Saharan Africa. Despite concurrent use of EI-ASMs and ARVs, the majority of participants showed CD4 counts >200 cells/mm³ and were virally suppressed. Carbamazepine was not associated with an increased risk of virological failure or ARV-resistant HIV.

Prevalence and characteristics of HIV drug resistance among antiretroviral treatment (ART) experienced adolescents and young adults living with HIV in Ndola, Zambia

BACKGROUND

HIV drug resistance (HIVDR) poses a threat to the HIV epidemic control in Zambia especially in sub-populations such as the 15-24 years where there is poor virological suppression. Understanding the prevalence and patterns of HIVDR in this population (15-24 years) will contribute to defining effective antiretroviral therapy (ART) regimens, improving clinical decision making, and supporting behavioral change interventions needed to achieve HIV epidemic control.

METHODS

A cross-sectional analysis of study enrollment data from the Project YES! Youth Engaging for Success randomized controlled trial was conducted. Participants were 15 to 24 years old, who knew their HIV status, and had been on ART for at least 6 months. All participants completed a survey and underwent viral load (VL) testing. Participants with viral failure (VL ≥1,000 copies/mL) underwent HIVDR testing which included analysis of mutations in the protease and reverse transcriptase genes.

RESULTS

A total of 99 out of 273 analyzed participants receiving ART had VL failure, of whom 77 had successful HIVDR amplification and analysis. Out of the 77, 75% (58) had at least one drug resistant mutation, among which 83% (48/58) required a drug change. Among the 58 with HIVDR mutations, the prevalence of at least one HIVDR mutation to nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs) were 81%, 65.5% and 1.7%. The mutation M184V which confers resistance to NRTI drugs of lamivudine (3TC) and emtricitabine (FTC) was the most common (81%) among NRTI associated mutations followed by K65R (34.5%) which is associated with both tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide fumarate (TAF) resistance. Thymidine analogue mutations (TAMs) which confer resistance primarily to zidovudine (AZT), stavudine (d4T) and other NRTIs were observed at 32.8%. Common TAMs were K70RTQNE (32.8%), K219QE (22.4%), D67N (17.2%) and T215IT (15.5%). The most common NNRTI associated mutation was the K103N (65.5%) which confers resistance to both efavirenz (EFV) and nevirapine (NVP). There was a relatively high occurrence of other NNRTI mutations V106A (36.2%), as well as Y188C (36.2%) and Y181C (36.2%) which confer resistance to etravirine.

CONCLUSIONS

There is a high prevalence of HIVDR including TAMs despite majority of these patients (90.48%) being on AZT or d4T sparing first line ART among the youth. Emergence of these mutations including the NNRTI associated mutations (Y181C and Y188C) may compromise future second- and third-line regimens in the absence of routine HIVDR testing. HIVDR monitoring at start of ART or at first-line failure can better inform clinical decision making and ART programing.

HIV-1 subtype diversity, drug resistance, and genetic transmission networks in men who have sex with men with virologic failure in antiretroviral therapy in Sichuan, China, 2011 to 2017

This study sought to examine the human immunodeficiency virus type 1 (HIV-1) genetic diversity on drug resistance among men who have sex with men (MSM) with virologic failure in antiretroviral therapy (ART), and investigate linking-associated factors for genetic transmission networks.Seven hundred and thirty-four HIV-positive MSM with virologic failure in ART were recruited into our study from 2011 to 2017. HIV-1 pol gene sequences were used for phylogenetic and genotypic drug resistance analyses. The drug resistance mutations were determined using the Stanford University HIV Drug Resistance Database. The genetic transmission networks were analyzed for CRF01_AE and CRF07_BC sequences by the genetic distance-based method.Of 734 subjects, 372 (50.68%) showed drug resistance, in which CRF01_AE and CRF07_BC were the predominating subtypes. Drug resistance more frequently occurred in non-nucleoside reverse transcriptase inhibitors (NNRTIs) treatment (48.64%), and followed by nucleoside reverse transcriptase inhibitors (NRTIs) (36.51%) and PIs (4.03%). The most common drug resistance-associated mutations in protease inhibitors (PIs), NRTIs and NNRTIs were K20I/R, M184V/I and K103N/KN, respectively. For 283CRF01_AE sequences, 64 (22.61%) fell into clusters at a genetic distance of 0.011, resulting in 17 clusters ranging in size from 2 to 16 individuals. For 230 CRF07_BC sequences, 66 (28.69%) were connected to at least one other sequence with 0.005 genetic distances, resulting in 8 clusters ranging in size from 2 to 52 individuals. Individuals who showed drug resistance to ART were less likely to fall into clusters than those who did not. The genetic linkage was robust by the exclusion of sites associated with drug resistance.CRF01_AE and CRF07_BC were the main strains among MSM with virologic failure in ART, and the drug resistance more frequently occurred in NNRTIs, followed by NRTIs and PIs. Genetic transmission networks revealed a complexity of transmission pattern, suggesting early-diagnosis and in-time intervention among MSM.

HIV-1 drug resistance before initiation or re-initiation of first-line antiretroviral therapy in low-income and middle-income countries: a systematic review and meta-regression analysis

Background

Pretreatment drug resistance in people initiating or re-initiating antiretroviral therapy (ART) containing non-nucleoside reverse transcriptase inhibitors (NNRTIs) might compromise HIV control in low-income and middle-income countries (LMICs). We aimed to assess the scale of this problem and whether it is associated with the intiation or re-initiation of ART in people who have had previous exposure to antiretroviral drugs.

Methods

This study was a systematic review and meta-regression analysis. We assessed regional prevalence of pretreatment drug resistance and risk of pretreatment drug resistance in people initiating ART who reported previous ART exposure. We systematically screened publications and unpublished datasets for pretreatment drug-resistance data in individuals in LMICs initiating or re-initiating first-line ART from LMICs. We searched for studies in PubMed and Embase and conference abstracts and presentations from the Conference on Retroviruses and Opportunistic Infections, the International AIDS Society Conference, and the International Drug Resistance Workshop for the period Jan 1, 2001, to Dec 31, 2016. To assess the prevalence of drug resistance within a specified region at any specific timepoint, we extracted study level data and pooled prevalence estimates within the region using an empty logistic regression model with a random effect at the study level. We used random effects meta-regression to relate sampling year to prevalence of pretreatment drug resistance within geographical regions.

Findings

We identified 358 datasets that contributed data to our analyses, representing 56 044 adults in 63 countries. Prevalence estimates of pretreatment NNRTI resistance in 2016 were 11·0% (7·5–15·9) in southern Africa, 10·1% (5·1–19·4) in eastern Africa, 7·2% (2·9–16·5) in western and central Africa, and 9·4% (6·6–13·2) in Latin America and the Caribbean. There were substantial increases in pretreatment NNRTI resistance per year in all regions. The yearly increases in the odds of pretreatment drug resistance were 23% (95% CI 16–29) in southern Africa, 17% (5–30) in eastern Africa, 17% (6–29) in western and central Africa, 11% (5–18) in Latin America and the Caribbean, and 11% (2–20) in Asia. Estimated increases in the absolute prevalence of pretreatment drug resistance between 2015 and 2016 ranged from 0·3% in Asia to 1·8% in southern Africa.

Interpretation

Pretreatment drug resistance is increasing at substantial rate in LMICs, especially in sub-Saharan Africa. In 2016, the prevalence of pretreatment NNRTI resistance was near WHO's 10% threshold for changing first-line ART in southern and eastern Africa and Latin America, underscoring the need for routine national HIV drug-resistance surveillance and review of national policies for first-line ART regimen composition.

Funding

Bill & Melinda Gates Foundation and World Health Organization.

Increasing HIV-1 Drug Resistance Between 2010 and 2012 in Adults Participating in Population-Based HIV Surveillance in Rural KwaZulu-Natal, South Africa

As more human immunodeficiency virus (HIV)–infected patients access combination antiretroviral therapy (cART), higher proportions of newly infected patients may be infected with drug-resistant viruses. Regular surveillance of transmitted drug resistance (TDR) is required in southern Africa where high rates of transmission persist despite rapid expansion of ART. Dried blood spot samples from cART-naive participants from two rounds of an annual population-based HIV surveillance program in rural KwaZulu-Natal were tested for HIV RNA, and samples with HIV RNA >10,000 copies/ml were genotyped for drug resistance. The 2009 surveillance of drug resistance mutation (SDRM) list was used for drug resistance interpretation. The data were added to previously published data from the same program, and the χ² test for trend was used to test for trend in estimated prevalence of any TDR. Seven hundred and one participants' data were analyzed: 67 (2010), 381 (2011), and 253 (2012). No TDR was detected in 2010. Years 2011 and 2012 had 18 participants with SDRMs 4.7% and 7.1%, respectively (p = .02, χ² test for trend). The nonnucleoside reverse transcriptase inhibitor mutation, K103N, was the most common mutation, occurring in 27 (3.8%) of the participants, while nucleoside reverse transcriptase inhibitor (NRTI) SDRMs were detected in 10 (1.4%) of the participants, of whom eight had only a single NRTI SDRM. The increase in levels of drug resistance observed in this population could be a signal of increasing transmission of drug-resistant HIV. Thus, continued surveillance is critical to inform public health policies around HIV treatment and prevention.

HIV-1 Drug Resistance Mutations: Potential Applications for Point-of-Care Genotypic Resistance Testing

The increasing prevalence of acquired and transmitted HIV-1 drug resistance is an obstacle to successful antiretroviral therapy (ART) in the low- and middle-income countries (LMICs) hardest hit by the HIV-1 pandemic. Genotypic drug resistance testing could facilitate the choice of initial ART in areas with rising transmitted drug resistance (TDR) and enable care-providers to determine which individuals with virological failure (VF) on a first- or second-line ART regimen require a change in treatment. An inexpensive near point-of-care (POC) genotypic resistance test would be useful in settings where the resources, capacity, and infrastructure to perform standard genotypic drug resistance testing are limited. Such a test would be particularly useful in conjunction with the POC HIV-1 viral load tests that are currently being introduced in LMICs. A POC genotypic resistance test is likely to involve the use of allele-specific point mutation assays for detecting drug-resistance mutations (DRMs). This study proposes that two major nucleoside reverse transcriptase inhibitor (NRTI)-associated DRMs (M184V and K65R) and four major NNRTI-associated DRMs (K103N, Y181C, G190A, and V106M) would be the most useful for POC genotypic resistance testing in LMIC settings. One or more of these six DRMs was present in 61.2% of analyzed virus sequences from ART-naïve individuals with intermediate or high-level TDR and 98.8% of analyzed virus sequences from individuals on a first-line NRTI/NNRTI-containing regimen with intermediate or high-level acquired drug resistance. The detection of one or more of these DRMs in an ART-naïve individual or in a individual with VF on a first-line NRTI/NNRTI-containing regimen may be considered an indication for a protease inhibitor (PI)-containing regimen or closer virological monitoring based on cost-effectiveness or country policy.

The prevalence and determinants of drug-resistance-associated mutations in the HIV-1-infected MSM population of Henan Province in China

To estimate the prevalence of human immunodeficiency virus (HIV) drug resistance (DR) in a population of men who have sex with men (MSM) from Henan Province of China and to identify the DR-associated HIV-1 mutations in these MSM. The HIV-positive status of the MSM subjects in this study was confirmed using ELISA and Western blotting. The MSM subjects were classified into non-treatment group (n = 106) and treatment group (n = 313). CD4(+) T-lymphocyte counts were obtained by flow cytometry, and viral load was measured by branched DNA (bDNA) signal amplification assay. HIV-1 genotypic resistance tests were performed by sequence analysis of the HIV-1 protease and reverse transcriptase genes. In the non-treatment group, 15 patients (14.2 %) displayed DR to non-nucleoside reverse transcriptase inhibitor (NNRTI). In the treatment group, the failure rate of viral suppression was 38.33 % and the DR rate was 33.2 %, which was higher than the rate observed in the non-treatment group (P < 0.05). The incidence of mutations corresponding to NNRTI resistance was significantly higher than the incidence of mutations corresponding to nucleoside reverse transcriptase inhibitor (NRTI) resistance (32.9 % vs. 26.5 %) in the cohort. After antiretroviral therapy (ART), the frequencies of K103N, G190A, Y181C, and V106A mutations were highly elevated. Logistic regression analysis results showed that duration of treatment, poor treatment compliance, drug abuse and homosexual orientation are the major risk factors for DR in this MSM population (all P < 0.05). Our results showed that DR-associated mutations in the HIV-1-infected MSM population increased significantly after ART. Furthermore, duration of treatment, poor treatment compliance, drug abuse and homosexual orientation were identified as the risk factors for DR in the MSM population from Henan Province in China.

Minority drug-resistant HIV-1 variants in treatment naïve East-African and Caucasian patients detected by allele-specific real-time PCR

Objective

To assess the presence of two major non-nucleoside reverse transcriptase inhibitors (NNRTI) drug resistance mutations (DRMs), Y181C and K103N, in minor viral quasispecies of treatment naïve HIV-1 infected East-African and Swedish patients by allele-specific polymerase chain reaction (AS-PCR).

Methods

Treatment naïve adults (n = 191) with three epidemiological backgrounds were included: 92 Ethiopians living in Ethiopia; 55 East-Africans who had migrated to Sweden; and 44 Caucasians living in Sweden. The pol gene was analysed by standard population sequencing and by AS-PCR for the detection of Y181C and K103N.

Results

The Y181C was detected in the minority quasispecies of six Ethiopians (6.5%), in two Caucasians (4.5%), and in one East-African (1.8%). The K103N was detected in one East- African (1.8%), by both methods. The proportion of mutants ranged from 0.25% to 17.5%. Additional DRMs were found in all three treatment naïve patient groups by population sequencing.

Conclusions

Major NNRTI mutations can be found by AS-PCR in minor quasispecies of treatment naïve HIV-1 infected Ethiopians living in Ethiopia, in East-African and Caucasian patients living in Sweden in whom population sequencing reveal wild-type virus only. Surveys with standard sequencing are likely to underestimate transmitted drug resistance and the presence of resistant minor quasispecies in treatment naïve patients should be topic for future large scale studies.

Short communication: Prevalence of HIV-1 transmitted drug resistance in Liberia

No data on HIV-transmitted drug resistance (TDR) are available in Liberia in which the HIV prevalence in the general population is estimated at 1.5%. The aim of the study was to assess the prevalence of TDR in HIV-1 from recently diagnosed and untreated patients living in Monrovia, Liberia. The study was performed in the John F. Kennedy Medical Center and in the Redemption Hospital, both located in Monrovia. All newly HIV-1 diagnosed patients attending voluntary counseling testing centers and antiretroviral therapy naive were consecutively included. Protease and reverse transcriptase (RT) regions sequencing was performed using the ANRS procedures (www.hivfrenchresistance.org). Drug resistance mutations (DRM) were identified according to the 2009 updated WHO surveillance DRM list. Among the 116 HIV-1-infected patients enrolled in the study, 85 (73%) were women. Protease and RT sequencing was successful in 109 (94%) and 102 (88%) samples, respectively. Seventy-five (66%) patients were infected with CRF02_AG. One DRM was observed in six samples, leading to a TDR prevalence of 5.9% (CI 95%=1.7-10.1). DRM were observed in two patients (2.0%; CI 95%=0.0-4.7), four patients (3.9%; CI 95%=0.1-7.7), and one patient (0.9%; CI 95%=0.0-2.7) for nucleoside RT inhibitors (NRTI), non-NRTI (NNRTI), and protease inhibitors, respectively. Overall, one patient exhibited dual class-resistant viruses, harboring NRTI and NNRTI resistance mutations (1.0%; CI 95%=0.0-2.9). This first survey study in Liberia reported a TDR prevalence of 5.9%, classified as moderate according to the WHO criteria, indicating that further surveillance is warranted to follow the level and evolution of TDR prevalence in recently HIV-1 diagnosed patients.

An affordable HIV-1 drug resistance monitoring method for resource limited settings

HIV-1 drug resistance has the potential to seriously compromise the effectiveness and impact of antiretroviral therapy (ART). As ART programs in sub-Saharan Africa continue to expand, individuals on ART should be closely monitored for the emergence of drug resistance. Surveillance of transmitted drug resistance to track transmission of viral strains already resistant to ART is also critical. Unfortunately, drug resistance testing is still not readily accessible in resource limited settings, because genotyping is expensive and requires sophisticated laboratory and data management infrastructure. An open access genotypic drug resistance monitoring method to manage individuals and assess transmitted drug resistance is described. The method uses free open source software for the interpretation of drug resistance patterns and the generation of individual patient reports. The genotyping protocol has an amplification rate of greater than 95% for plasma samples with a viral load >1,000 HIV-1 RNA copies/ml. The sensitivity decreases significantly for viral loads <1,000 HIV-1 RNA copies/ml. The method described here was validated against a method of HIV-1 drug resistance testing approved by the United States Food and Drug Administration (FDA), the Viroseq genotyping method. Limitations of the method described here include the fact that it is not automated and that it also failed to amplify the circulating recombinant form CRF02_AG from a validation panel of samples, although it amplified subtypes A and B from the same panel.

Dropout and re-enrollment: implications for epidemiological projections of treatment programs

OBJECTIVE

EMOD-HIV v0.8 has been used to estimate the potential impact of expanding treatment guidelines to allow earlier initiation of antiretroviral therapy (ART) in sub-Saharan Africa with current or improved treatment coverage. In generating these results, a model must additionally make assumptions about the rates of dropout and re-initiation into ART programs before and after the program change, about which little is known. The objective of this work is to rigorously analyze modeling assumptions and the sensitivity of model results with respect to relevant mechanisms and parameters.

METHODS

We varied key model assumptions pertaining to ART dropout and re-enrollment to analyze their effect on the cost, impact, and cost-effectiveness of expanding treatment guidelines, and of expanding coverage via improved testing and linkage to care. Additionally, we performed a sensitivity analysis of 17 relevant model parameters.

SETTING

South Africa.

RESULTS

Allowing re-initiation of ART irrespective of prior treatment doubled the cost and impact of expanding treatment guidelines, as compared with a scenario in which re-initiation could only be triggered by a health event (AIDS symptoms, diagnosis of a partner, or an antenatal care visit). Increasing the probability of 'voluntary' re-initiation (not triggered by a health event) was the most cost-effective way to improve the treatment program, especially in the short term because it provided immediate benefits to those who would otherwise have delayed re-initiation until the onset of AIDS symptoms. However, the maximum impact of this change was limited compared with expanding coverage through improvements in testing and linkage to care. Beyond improvements in coverage and re-initiation, further gains could be made by improving retention in care. Only with optimal retention in care was expansion of guidelines cost-saving after 20 years due to reductions in transmission. Re-initiation did not reduce transmission sufficiently to make a guideline change cost-effective due to transmission that occurred while patients were away from care. Sensitivity analysis suggested that enormous health benefits could be attained by improving treatment regimens to have higher efficacy at preventing transmission, increasing the proportion of the population with access to improved healthcare, and reducing 'leaks' in the 'cascade of care.' Increasing the proportion of individuals who receive CD4 cell results was particularly cost-effective at baseline levels of coverage, and increasing retention on ART was particularly cost-effective with expanded coverage.

CONCLUSION

This analysis provides a sense of the magnitude of uncertainty in program cost and impact that policy-makers could anticipate in the face of uncertain future programmatic changes. Our findings suggest that increasing re-initiation is the most cost-effective means of initial program improvement, especially in the short term, but that improvements in retention are necessary in order to reap the full transmission-blocking benefits of a test-and-treat program in the long term.

Transmitted antiretroviral drug resistance in newly HIV-infected and untreated patients in Ségou and Bamako, Mali

The WHO recommends regular surveillance for transmitted antiretroviral drug-resistant viruses in HIV antiretroviral treatment (ART)-naive patients in resource-limited settings. This study aimed to assess the prevalence of mutations associated with resistance in ART-naive patients newly diagnosed with HIV in Bamako and Ségou in Mali. HIV-positive patients who never received ART were recruited in Bamako and Ségou, Mali. The reverse transcriptase (RT) and protease (PR) genes of these patients were sequenced by the "ViroSeq" method. Analysis and interpretation of the resistance were made according to the WHO 2009 list of drug resistance mutations. In all, 51/54 (94.4%) sample patients were sequenced. The median age (IQR) of our patients was 24 (22-27) years and the median CD4 count was 380 (340-456) cells/mm(3). The predominant subtype was recombinant HIV-1 CRF02_AG (66.7%) followed by CRF06_cpx (12%) and CRF09_cpx (4%). Four patients had mutations associated with resistance, giving an overall prevalence of resistance estimated at 7.9%. There were two (4%) patients with nucleoside reverse transcriptase inhibitor (NRTI) mutations (one M184V and one T215Y), two (4%) with non-NRTI mutations (two K103N), and one (2%) with a protease inhibitor mutation (one I54V). The prevalence of primary resistance in newly infected patients in Mali is moderate (7.9%). This indicates that the standard NNRTI-based first-line regimen used in Mali is suboptimal for some patients. This study should be done regularly to inform clinical practice.

Comparison of predicted susceptibility between genotype and virtual phenotype HIV drug resistance interpretation systems among treatment-naive HIV-infected patients in Asia: TASER-M cohort analysis

Background

Accurate interpretation of HIV drug resistance (HIVDR) testing is challenging, yet important for patient care. We compared genotyping interpretation, based on the Stanford University HIV Drug Resistance Database (Stanford HIVdb), and virtual phenotyping, based on the Janssen Diagnostics BVBA’s vircoTYPE™ HIV-1, and investigated their level of agreement in antiretroviral (ARV) naive patients in Asia, where non-B subtypes predominate.

Methods

Sequences from 1301 ARV-naive patients enrolled in the TREAT Asia Studies to Evaluate Resistance – Monitoring Study (TASER-M) were analysed by both interpreting systems. Interpretations from both Stanford HIVdb and vircoTYPE™ HIV-1 were initially grouped into 2 levels: susceptible and non-susceptible. Discrepancy was defined as a discordant result between the susceptible and non-susceptible interpretations from the two systems for the same ARV. Further analysis was performed when interpretations from both systems were categorised into 3 levels: susceptible, intermediate and resistant; whereby discrepancies could be categorised as major discrepancies and minor discrepancies. Major discrepancy was defined as having a susceptible result from one system and resistant from the other. Minor discrepancy corresponded to having an intermediate interpretation in one system, with a susceptible or resistant result in the other. The level of agreement was analysed using the prevalence adjusted bias adjusted kappa (PABAK).

Results

Overall, the agreement was high, with each ARV being in “almost perfect agreement”, using Landis and Koch’s categorisation. Highest discordance was observed for efavirenz (75/1301, 5.8%), all arising from susceptible Stanford HIVdb versus non-susceptible vircoTYPE™ HIV-1 predictions. Protease Inhibitors had highest level of concordance with PABAKs all above 0.99, followed by Nucleoside Reverse Transcriptase Inhibitors with PABAKs above 0.97 and non-NRTIs with the lowest PABAK of 0.88. The 68/75 patients with discordant efavirenz results harboured the V179D/E mutations compared to 7/1226 with no efavirenz discrepancy (p-value <0.001). In the 3-level comparison, all but one of the discrepancies was minor.

Conclusions

The two systems agreed well with lowest concordance observed for efavirenz. When interpreting HIVDR, especially in non-B subtypes, clinical correlation is crucial, in particular when efavirenz resistance is interpreted based on V179D/E.

Prevalence of transmitted HIV drug resistance among newly diagnosed antiretroviral therapy-naive pregnant women in Lilongwe and Blantyre, Malawi

In 2006, a survey of transmitted human immunodeficiency virus (HIV) drug resistance (TDR) was conducted in Lilongwe, Malawi. The survey followed the World Health Organization method to classify TDR to nucleoside reverse transcriptase inhibitors (NRTIs), nonnucleoside reverse transcriptase inhibitors (NNRTIs), and protease inhibitors (PIs) among primigravid women aged <25 years. Results of the 2006 survey showed <5% TDR in all drug classes. In 2009, TDR surveys using the same method were repeated in Lilongwe and expanded to Blantyre. Findings show that in Lilongwe TDR to NRTIs and PIs was <5%, whereas TDR to NNRTIs was 5%-15%. In Blantyre, TDR was <5% to all drug classes. Observed moderate TDR in Lilongwe is cause for concern and signals the need for closer monitoring of Malawi's antiretroviral therapy program.

Primary drug resistance in South Africa: data from 10 years of surveys

HIV-1 transmitted drug resistance (TDR) could reverse the gains of antiretroviral rollout. To ensure that current first-line therapies remain effective, TDR levels in recently infected treatment-naive patients need to be monitored. A literature review and data mining exercise was carried out to determine the temporal trends in TDR in South Africa. In addition, 72 sequences from seroconvertors identified from Africa Centre's 2010 HIV surveillance round were also examined for TDR. Publicly available data on TDR were retrieved from GenBank, curated in RegaDB, and analyzed using the Calibrated Population Resistance Program. There was no evidence of TDR from the 2010 rural KwaZulu Natal samples. Ten datasets with a total of 1618 sequences collected between 2000 and 2010 were pooled to provide a temporal analysis of TDR. The year with the highest TDR rate was 2002 [6.67%, 95% confidence interval (CI): 3.09-13.79%; n=6/90]. After 2002, TDR levels returned to <5% (WHO low-level threshold) and showed no statistically significant increase in the interval between 2002 and 2010. The most common mutations were associated with NNRTI resistance, K103N, followed by Y181C and Y188C/L. Five sequences had multiple resistance mutations associated with NNRTI resistance. There is no evidence of TDR in rural KwaZulu-Natal. TDR levels in South Africa have remained low following a downward trend since 2003. Continuous vigilance in monitoring of TDR is needed as more patients are initiated and maintained onto antiretroviral therapy.

HIV-1 phenotypic reverse transcriptase inhibitor drug resistance test interpretation is not dependent on the subtype of the virus backbone

To date, the majority of HIV-1 phenotypic resistance testing has been performed with subtype B virus backbones (e.g. HXB2). However, the relevance of using this backbone to determine resistance in non-subtype B HIV-1 viruses still needs to be assessed. From 114 HIV-1 subtype C clinical samples (36 ARV-naïve, 78 ARV-exposed), pol amplicons were produced and analyzed for phenotypic resistance using both a subtype B- and C-backbone in which the pol fragment was deleted. Phenotypic resistance was assessed in resulting recombinant virus stocks (RVS) for a series of antiretroviral drugs (ARV's) and expressed as fold change (FC), yielding 1660 FC comparisons. These Antivirogram® derived FC values were categorized as having resistant or sensitive susceptibility based on biological cut-off values (BCOs). The concordance between resistance calls obtained for the same clinical sample but derived from two different backbones (i.e. B and C) accounted for 86.1% (1429/1660) of the FC comparisons. However, when taking the assay variability into account, 95.8% (1590/1660) of the phenotypic data could be considered as being concordant with respect to their resistance call. No difference in the capacity to detect resistance associated with M184V, K103N and V106M mutations was noted between the two backbones. The following was concluded: (i) A high level of concordance was shown between the two backbone phenotypic resistance profiles; (ii) Assay variability is largely responsible for discordant results (i.e. for FC values close to BCO); (iii) Confidence intervals should be given around the BCO's, when assessing resistance in HIV-1 subtype C; (iv) No systematic resistance under- or overcalling of subtype C amplicons in the B-backbone was observed; (v) Virus backbone subtype sequence variability outside the pol region does not contribute to phenotypic FC values. In conclusion the HXB2 virus backbone remains an acceptable vector for phenotyping HIV-1 subtype C pol amplicons.

Grappling with HIV transmission risks: narratives of rural women in eastern Kenya living with HIV

As people live longer and more productively with HIV infection, issues of agency in reducing HIV risk are particularly important for HIV-infected women living in high prevalence, underresourced countries such as Kenya. Because of their gendered lives, in that being masculine is associated with dominance and being feminine is associated with passiveness, women in rural Kenya must cope with continued HIV transmission risk even after knowing they are infected with HIV. In this narrative interview study, informed by theories of gender and postcolonial feminism, we examined personal accounts of HIV risk and risk reduction of 20 rural women in eastern Kenya who were living with HIV. From our analysis of the women's narratives, two major themes emerged: gender-based obstacles even in the context of a known HIV diagnosis, and struggles with economic pressures amid HIV risks. Implications for policy, programs, and research are discussed.

HIV testing and antiretroviral treatment strategies for prevention of HIV infection: impact on antiretroviral drug resistance

'Test and treat' is a strategy in which widespread screening for human immunodeficiency virus (HIV) is followed by immediate antiretroviral therapy for those testing positive, thereby potentially reducing infectiousness in larger cohorts of infected patients. However, there is a concern that test and treat could lead to increased the levels of transmissible drug-resistant HIV, especially if viral load and/or drug resistance is not routinely monitored. Reviews of the existing literature show that up to now, even in the absence of laboratory tests, drug resistance has not created major problems in sub-Saharan Africa. Here, we discuss the current evidence for the effectiveness of a preventive test and treat approach and the challenges and implications for daily clinical practice and public health.

The Achilles' Heel of HIV Treatment for Prevention: History of Sexually Transmitted Coinfections among People Living with HIV/AIDS Receiving Antiretroviral Therapies

BACKGROUND

Antiretroviral therapies (ARTs) offer promising new avenues for HIV prevention. Unfortunately, people infected with HIV who have co-occurring sexually transmitted infections (STIs) are more infectious than suggested by the amount of virus in their peripheral blood. We examined the history of sexually transmitted coinfections in people living with HIV.

METHODS

People living with HIV/AIDS completed confidential computerized interviews that assessed history of STI, sexual behaviors, and STI knowledge.

RESULTS

Among 414 men and 156 women currently receiving ART, 53% had been diagnosed with at least 1 STI since testing HIV positive; 24% women, 19% men, and 11% transgender persons had been diagnosed with an STI in the past year. History of STI was associated with younger age, greater STI knowledge, substance use, and ART nonadherence.

CONCLUSIONS

Aggressive strategies for detecting and treating STI in people receiving ART will be necessary to achieve protective benefits.

High prevalence of antiretroviral drug resistance among HIV-1-untreated patients in Guinea-Conakry and in Niger

BACKGROUND

The aim of the study was to assess the prevalence of antiretroviral drug resistance mutations in HIV-1 from recently diagnosed and untreated patients living in Conakry, Guinea-Conakry and in Niamey, Niger.

METHODS

The study was performed in two countries of Western Africa - Guinea-Conakry and Niger - using the same survey method in both sites. All newly HIV-1 diagnosed patients, naive of antiretroviral drugs, were consecutively included during September 2009 in each of the two sites. Protease and reverse transcriptase sequencing was performed using the ANRS procedures. Drug resistance mutations were identified according to the 2009 update surveillance drug resistance mutations.

RESULTS

In Conakry, 99 patients were included, most of whom (89%) were infected with CRF02_AG recombinant virus. Resistance analysis among the 93 samples showed that ≥1 drug resistance mutation was observed in 8 samples, leading to a prevalence of primary resistance of 8.6% (95% CI 2.91-14.29%). In Niamey, 96 patients were included; a high diversity in HIV-1 subtypes was observed with 47 (51%) patients infected with CRF02_AG. Resistance analysis performed among the 92 samples with successful genotypic resistance test showed that ≥1 drug resistance mutation was observed in 6 samples, leading to a prevalence of primary resistance of 6.5% (95% CI 1.50-11.50%).

CONCLUSIONS

We reported the first antiretroviral drug resistance survey studies in antiretroviral-naive patients living in Guinea-Conakry and in Niger. The prevalence of resistance was between 6% and 9% in both sites, which is higher than most of the other countries from Western Africa region.

HIV-1 drug resistance in antiretroviral-naive individuals in sub-Saharan Africa after rollout of antiretroviral therapy: a multicentre observational study

BACKGROUND

There are few data on the epidemiology of primary HIV-1 drug resistance after the roll-out of antiretroviral treatment (ART) in sub-Saharan Africa. We aimed to assess the prevalence of primary resistance in six African countries after ART roll-out and if wider use of ART in sub-Saharan Africa is associated with rising prevalence of drug resistance.

METHODS

We did a cross-sectional study in antiretroviral-naive adults infected with HIV-1 who had not started first-line ART, recruited between 2007 and 2009 from 11 regions in Kenya, Nigeria, South Africa, Uganda, Zambia, and Zimbabwe. We did population-based sequencing of the pol gene on plasma specimens with greater than 1000 copies per mL of HIV RNA. We identified drug-resistance mutations with the WHO list for transmitted resistance. The prevalence of sequences containing at least one drug-resistance mutation was calculated accounting for the sampling weights of the sites. We assessed the risk factors of resistance with multilevel logistic regression with random coefficients.

FINDINGS

2436 (94.1%) of 2590 participants had a pretreatment genotypic resistance result. 1486 participants (57.4%) were women, 1575 (60.8%) had WHO clinical stage 3 or 4 disease, and the median CD4 count was 133 cells per μL (IQR 62-204). Overall sample-weighted drug-resistance prevalence was 5.6% (139 of 2436; 95% CI 4.6-6.7), ranging from 1.1% (two of 176; 0.0-2.7) in Pretoria, South Africa, to 12.3% (22 of 179; 7.5-17.1) in Kampala, Uganda. The pooled prevalence for all three Ugandan sites was 11.6% (66 of 570; 8.9-14.2), compared with 3.5% (73 of 1866; 2.5-4.5) for all other sites. Drug class-specific resistance prevalence was 2.5% (54 of 2436; 1.8-3.2) for nucleoside reverse-transcriptase inhibitors (NRTIs), 3.3% (83 of 2436; 2.5-4.2) for non-NRTIs (NNRTIs), 1.3% (31 of 2436; 0.8-1.8) for protease inhibitors, and 1.2% (25 of 2436; 0.7-1.7) for dual-class resistance to NRTIs and NNRTIs. The most common drug-resistance mutations were K103N (43 [1.8%] of 2436), thymidine analogue mutations (33 [1.6%] of 2436), M184V (25 [1.2%] of 2436), and Y181C/I (19 [0.7%] of 2436). The odds ratio for drug resistance associated with each additional year since the start of the ART roll-out in a region was 1.38 (95% CI 1.13-1.68; p=0.001).

INTERPRETATION

The higher prevalence of primary drug resistance in Uganda than in other African countries is probably related to the earlier start of ART roll-out in Uganda. Resistance surveillance and prevention should be prioritised in settings where ART programmes are scaled up.

FUNDING

Ministry of Foreign Affairs of the Netherlands.

Surveillance of transmitted antiretroviral drug resistance among HIV-1 infected women attending antenatal clinics in Chitungwiza, Zimbabwe

The rapid scale-up of highly active antiretroviral therapy (HAART) and use of single dose Nevirapine (SD NVP) for prevention of mother-to-child transmission (pMTCT) have raised fears about the emergence of resistance to the first line antiretroviral drug regimens. A cross-sectional study was conducted to determine the prevalence of primary drug resistance (PDR) in a cohort of young (<25 yrs) HAART-naïve HIV pregnant women attending antenatal clinics in Chitungwiza, Zimbabwe. Whole blood was collected in EDTA for CD4 counts, viral load, serological estimation of duration of infection using the BED Calypte assay and genotyping for drug resistance. Four hundred and seventy-one women, mean age 21 years; SD: 2.1 were enrolled into the study between 2006 and 2007. Their median CD4 count was 371cells/µL; IQR: 255–511 cells/µL. Two hundred and thirty-six samples were genotyped for drug resistance. Based on the BED assay, 27% were recently infected (RI) whilst 73% had long-term infection (LTI). Median CD4 count was higher (p<0.05) in RI than in women with LTI. Only 2 women had drug resistance mutations; protease I85V and reverse transcriptase Y181C. Prevalence of PDR in Chitungwiza, 4 years after commencement of the national ART program remained below WHO threshold limit (5%). Frequency of recent infection BED testing is consistent with high HIV acquisition during pregnancy. With the scale-up of long-term ART programs, maintenance of proper prescribing practices, continuous monitoring of patients and reinforcement of adherence may prevent the acquisition and transmission of PDR.